fix #4546

[oweals/gnunet.git] / src / nat / gnunet-helper-nat-client.c

diff --git a/src/nat/gnunet-helper-nat-client.c b/src/nat/gnunet-helper-nat-client.c
index f30348cc46dac2824906e82ac2ecd8d6564a4935..d9129afb08bafd8d5196a17e038a52db98bfb0e8 100644 (file)
--- a/src/nat/gnunet-helper-nat-client.c
+++ b/src/nat/gnunet-helper-nat-client.c
@@ -1,6 +1,6 @@
 /*
      This file is part of GNUnet.
-     (C) 2010 Christian Grothoff (and other contributing authors)
+     Copyright (C) 2010 GNUnet e.V.
 
      GNUnet is free software; you can redistribute it and/or modify
      it under the terms of the GNU General Public License as published
@@ -14,8 +14,8 @@
 
      You should have received a copy of the GNU General Public License
      along with GNUnet; see the file COPYING.  If not, write to the
-     Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-     Boston, MA 02111-1307, USA.
+     Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+     Boston, MA 02110-1301, USA.
 */
 
 /**
@@ -61,6 +61,11 @@
 #include <netinet/ip_icmp.h>
 #include <netinet/in.h>
 
+/* The following constant is missing from FreeBSD 9.2 */
+#ifndef ICMP_TIME_EXCEEDED
+#define ICMP_TIME_EXCEEDED 11
+#endif
+
 /**
  * Must match IP given in the server.
  */
@@ -232,7 +237,11 @@ send_icmp_udp (const struct in_addr *my_ip, const struct in_addr *other)
   off = 0;
   ip_pkt.vers_ihl = 0x45;
   ip_pkt.tos = 0;
+#ifdef FREEBSD
+  ip_pkt.pkt_len = sizeof (packet); /* Workaround PR kern/21737 */
+#else
   ip_pkt.pkt_len = htons (sizeof (packet));
+#endif
   ip_pkt.id = htons (PACKET_ID);
   ip_pkt.flags_frag_offset = 0;
   ip_pkt.ttl = 128;
@@ -301,7 +310,7 @@ send_icmp_udp (const struct in_addr *my_ip, const struct in_addr *other)
   }
   else if (sizeof (packet) != (size_t) err)
   {
-    fprintf (stderr, "Error: partial send of ICMP message\n");
+    fprintf (stderr, "Error: partial send of ICMP message with size %lu\n", (unsigned long) off);
   }
 }
 
@@ -329,7 +338,11 @@ send_icmp (const struct in_addr *my_ip, const struct in_addr *other)
   off = 0;
   ip_pkt.vers_ihl = 0x45;
   ip_pkt.tos = 0;
+#ifdef FREEBSD
+  ip_pkt.pkt_len = sizeof (packet); /* Workaround PR kern/21737 */
+#else
   ip_pkt.pkt_len = htons (sizeof (packet));
+#endif
   ip_pkt.id = htons (PACKET_ID);
   ip_pkt.flags_frag_offset = 0;
   ip_pkt.ttl = IPDEFTTL;
@@ -406,92 +419,93 @@ send_icmp (const struct in_addr *my_ip, const struct in_addr *other)
 }
 
 
-/**
- * Create an ICMP raw socket for writing.
- *
- * @return -1 on error
- */
-static int
-make_raw_socket ()
+int
+main (int argc, char *const *argv)
 {
   const int one = 1;
-  int ret;
+  struct in_addr external;
+  struct in_addr target;
+  uid_t uid;
+  unsigned int p;
+  int raw_eno;
+  int global_ret;
+
+  /* Create an ICMP raw socket for writing (only operation that requires root) */
+  rawsock = socket (AF_INET, SOCK_RAW, IPPROTO_RAW);
+  raw_eno = errno; /* for later error checking */
 
-  ret = socket (AF_INET, SOCK_RAW, IPPROTO_RAW);
-  if (-1 == ret)
+  /* now drop root privileges */
+  uid = getuid ();
+#ifdef HAVE_SETRESUID
+  if (0 != setresuid (uid, uid, uid))
   {
-    fprintf (stderr, "Error opening RAW socket: %s\n", strerror (errno));
-    return -1;
+    fprintf (stderr, "Failed to setresuid: %s\n", strerror (errno));
+    global_ret = 1;
+    goto cleanup;
+  }
+#else
+  if (0 != (setuid (uid) | seteuid (uid)))
+  {
+    fprintf (stderr, "Failed to setuid: %s\n", strerror (errno));
+    global_ret = 2;
+    goto cleanup;
+  }
+#endif
+  if (-1 == rawsock)
+  {
+    fprintf (stderr, "Error opening RAW socket: %s\n", strerror (raw_eno));
+    global_ret = 3;
+    goto cleanup;
   }
   if (0 !=
-      setsockopt (ret, SOL_SOCKET, SO_BROADCAST, (char *) &one, sizeof (one)))
+      setsockopt (rawsock, SOL_SOCKET, SO_BROADCAST, (char *) &one, sizeof (one)))
   {
     fprintf (stderr, "setsockopt failed: %s\n", strerror (errno));
-    close (ret);
-    return -1;
+    global_ret = 4;
+    goto cleanup;
   }
   if (0 !=
-      setsockopt (ret, IPPROTO_IP, IP_HDRINCL, (char *) &one, sizeof (one)))
+      setsockopt (rawsock, IPPROTO_IP, IP_HDRINCL, (char *) &one, sizeof (one)))
   {
     fprintf (stderr, "setsockopt failed: %s\n", strerror (errno));
-    close (ret);
-    return -1;
+    global_ret = 5;
+    goto cleanup;
   }
-  return ret;
-}
-
-
-int
-main (int argc, char *const *argv)
-{
-  struct in_addr external;
-  struct in_addr target;
-  uid_t uid;
-  unsigned int p;
 
   if (4 != argc)
   {
     fprintf (stderr,
              "This program must be started with our IP, the targets external IP, and our port as arguments.\n");
-    return 1;
+    global_ret = 6;
+    goto cleanup;
   }
   if ((1 != inet_pton (AF_INET, argv[1], &external)) ||
       (1 != inet_pton (AF_INET, argv[2], &target)))
   {
     fprintf (stderr, "Error parsing IPv4 address: %s\n", strerror (errno));
-    return 1;
+    global_ret = 7;
+    goto cleanup;
   }
   if ((1 != sscanf (argv[3], "%u", &p)) || (0 == p) || (0xFFFF < p))
   {
     fprintf (stderr, "Error parsing port value `%s'\n", argv[3]);
-    return 1;
+    global_ret = 8;
+    goto cleanup;
   }
   port = (uint16_t) p;
   if (1 != inet_pton (AF_INET, DUMMY_IP, &dummy))
   {
     fprintf (stderr, "Internal error converting dummy IP to binary.\n");
-    return 2;
+    global_ret = 9;
+    goto cleanup;
   }
-  if (-1 == (rawsock = make_raw_socket ()))
-    return 2;
-  uid = getuid ();
-#ifdef HAVE_SETRESUID
-  if (0 != setresuid (uid, uid, uid))
-  {
-    fprintf (stderr, "Failed to setresuid: %s\n", strerror (errno));
-    return 3;
-  }
-#else
-  if (0 != (setuid (uid) | seteuid (uid)))
-  {
-    fprintf (stderr, "Failed to setuid: %s\n", strerror (errno));
-    return 6;
-  }
-#endif
   send_icmp (&external, &target);
   send_icmp_udp (&external, &target);
-  close (rawsock);
-  return 0;
+  global_ret = 0;
+ cleanup:
+  if (-1 != rawsock)
+    (void) close (rawsock);
+  return global_ret;
 }
 
 /* end of gnunet-helper-nat-client.c */